13 replies to this topic

[GemBoy]

Hi!
I'm preparing (slowly:/) to swap engine in my Manta. It will be probably C20NE, because it's very cheap (2-3 times cheaper than Red Box) and i don't need much power now, i just need a working engine, cause my 20S is pretty funked up...
Other candidate was M50B20 2.0 straight-6 from BMW, but i heard it's not so reliable as C20NE...

What gearbox i should use? should it be the one paired to C20NE, or i should look for different one?
I have 4-gear box, so it should be swapped for some 5-gear box.
It's pretty cheap, used gearbox from X20XEV cost like 30 pounds, so maybe it is good idea to buy newer one?
But will it fit?

What to do with rear axle? Is a rear axle from Omega A/B will fit into Manta?
Should i look for axle from auto-gearbox version, is it true they are not so worn out as manual versions?
Again should i use rear axle from 2.0 8V or i should look for something stronger for future use?
Complete rear axle from 2.5 V6 cost like 50 pounds so it's not expensive... are there big differencies between them?

sorry for newbie questions, but it is my first car for rebuild, of course i will have help from good mechanic, but he's working mostly on fords and wv's, so i need some knowledge to start with... I don't want to go buy something that will not fit...

[spiney_norman]

Gearbox - you'll need either an 1800 Manta box or a box from a rear wheel drive 2.0 Carlton/Omega A. The box from the Omega B V6 will fit but that has a hydraulic clutch whereas the Manta has a cable clutch. Using the box that's already on the C20NE depends on what the engine came from, if it was from a Carlton/Omega A then you should be alright, but Cavaliers/Vectras were front wheel drive so the box can't be used in a Manta.

As for the rear axle, the standard Manta one will be fine with a C20NE. The Omega axle can be fitted but is a lot of work as the Omegas had independent rear suspension and the Manta had a live axle, two completely different setups.

The other thing to consider is that for a C20NE to fit a Manta you'll need the 1800 Manta alloy big wing sump to clear the crossmember. The work is basically the same as converting to a C20XE but with less power when it's finished.

Where in the world are you? Sounds like it might be easier for you to get a replacement 2.0S engine?

[GemBoy]

Thanks for advices. I'll look for Omega A as a donor.
One more question about gearbox. Can i use C20NE from Astra and gearbox for C20NE from Omega A?
Are there any differencies in engine-gearbox connection, or is it plug&play?
Cause today i saw the auction for Astra MK3 with C20NE, very nice donor sold for ~150pounds, even with LPG installation, bargain price...
http://allegro.pl/po...2051456698.html
i didn't bid cause i was not sure about gearbox fitting :/

About the rear axle, sorry, that was stupid question, my mechanic told me about that before and i completly forgot.
I will stick to the original one for now, but are there any known cars with live axle that could be used in Manta?

I live in Poland (i forgot to fill my profile). There is quite hard to get parts for so old cars thats why i want
to put newer engine instead of original one (original was 1.9S by the way .
I don't want to fix the old one either cause it will cost me at least 300+ pounds, it is not worth in my opinion to repair
old carburettor engine which i cannot trust anyway, and it's working on 3 cyl since yesterday, so i'll put it in a storage for better times

What is wrong with the sump, is it different in size, deeper? It is like impossible for me to find Manta 1.8 sump,
i found one for Ascona, but i suppose it is the wrong one? Pictures are below:
http://allegro.pl/mi...2076698043.html
Is there any way to use other sump than this impossible-to-find-Manta-1.8 one?

Thanks for patience

[spiney_norman]

Yes, you can use the Astra engine and the Omega box. Might need to buy a new clutch to suit the Omega box though, but I'm not an expert on these engines.

There are other live axles that could possibly be used, but it's not really worth doing unless you're going for massive power gains, the standard axle is strong enough for at least 200bhp.

As for the sump, the problem is that the C20NE was mainly used in front wheel drive cars, and the Ascona sump in your link will not clear the front suspension crossmember on a Manta. I think an Omega A sump will be different too, as they had a very different front suspension setup to a Manta. I've heard that a company in this country called Yukspeed make a steel sump to suit rear wheel drive red top conversions, but I've also heard that it's no good for a Manta as the clutch cable won't clear the sump. I think you'll either have to find a Manta 1.8 sump or find someone very good at welding to fabricate a new sump or heavily modify a front wheel drive sump.

You say your 1.9S was running on 3 cylinders, have you checked simple things like spark plugs, distributor cap, spark plug leads etc? Sounds like fixing your original engine would be cheaper and easier than sourcing the parts to swap to a C20NE unless there's something else wrong with it?

[rallycinq]

I'd agree with Spiney norman on this.

The C20NE is a good engine, but to make it fit a 1.9S car is quite a lot of work, because the exhaust is on the other side of the engine so you would need to source a new exhaust manifold and system as well as the sump. Once you add that to the price of the engine and gearbox, you will be close to the price for rebuilding your 1.9, even if it needs a rebore.

Do a compression test on the 1.9 before making rash decisions about cahnging engines.

Cheers

david

[GemBoy]

spiney_norman, on 25 January 2012 - 10:19 PM, said:

As for the sump, the problem is that the C20NE was mainly used in front wheel drive cars, and the Ascona sump in your link will not clear the front suspension crossmember on a Manta. I think an Omega A sump will be different too, as they had a very different front suspension setup to a Manta. I've heard that a company in this country called Yukspeed make a steel sump to suit rear wheel drive red top conversions, but I've also heard that it's no good for a Manta as the clutch cable won't clear the sump. I think you'll either have to find a Manta 1.8 sump or find someone very good at welding to fabricate a new sump or heavily modify a front wheel drive sump.

I just read about this Yukspeed on other forum (migweb) that their sump is piece of $hit and it's still cost 160 pounds.
I also found something interesting there:
http://www.migweb.co...tml#post4107832
Some guy combined 2.0 8V sump with bottom part of 3.0 V6 sump. What do you think about it?
Assuming they're both made from steel it's 20 minute wielding job using 30pounds worth V6 sump as donor.
Sound cheap and possible

Omega V6 sump for reference:



As i found out here: http://www.opelmanta16v.4mg.com/
Oil pickup pipe in C20NE seems almost the same as in 1.8, will it fit without any preparing?

spiney_norman, on 25 January 2012 - 10:19 PM, said:

You say your 1.9S was running on 3 cylinders, have you checked simple things like spark plugs, distributor cap, spark plug leads etc? Sounds like fixing your original engine would be cheaper and easier than sourcing the parts to swap to a C20NE unless there's something else wrong with it?

There was little misunderstand here, my Manta was originally 19S (it's still in car docs) but there is 20S under the bonnet now.
I checked today in motorbike-way exhaust manifolds, the outside ones gets warn right after start, so i'll check spark plugs and leads in middle cylinders tomorrow (it's dark already :/). Also i will check compression on cylinders, maybe it's funked already ;p
Yes, there is lot wrong with this engine, it's overheating, Probably engine block is broken, fumes are going to water cooling circuit and also i found some water in oil recently. That's why i don't think it's worth repairing.

rallycinq, on 25 January 2012 - 11:22 PM, said:

The C20NE is a good engine, but to make it fit a 1.9S car is quite a lot of work, because the exhaust is on the other side of the engine so you would need to source a new exhaust manifold and system as well as the sump. Once you add that to the price of the engine and gearbox, you will be close to the price for rebuilding your 1.9, even if it needs a rebore. Do a compression test on the 1.9 before making rash decisions about cahnging engines. Cheers david

My friend is motorbike maniac, and he build quite a lot of exhaust manifolds for motorbikes, we both think he'll be capable of wielding one for Manta too
I wrote about sump problem above. I'll check the compression anyway, tomorrow.

[spiney_norman]

I may be wrong, but that sump still doesn't look like it would clear the Manta suspension crossmember. If your mate's a good welder then he may well be able to make up a sump using bits from the original C20NE one, but from the picture you just posted it looks like the Omega V6 sump is mostly alloy, not steel.

As for your 2.0S, if there's water in the oil and it's overheating then a new head gasket should fix it. That would be much easier than sourcing parts for a C20NE conversion and making your own sump.

[GemBoy]

spiney_norman, on 26 January 2012 - 06:47 PM, said:

As for your 2.0S, if there's water in the oil and it's overheating then a new head gasket should fix it. That would be much easier than sourcing parts for a C20NE conversion and making your own sump.

Sorry, i forgot to mention before, head was taken for renovation few months ago and fitted (of course) with new head gasket, it didn't help.
Guy who worked on that head told me, when it was ready, that he is sure that problem is in block not in the head. Later i checked with other mechanician and he told me the same,  since when he told me what's the cost of reviving this engine i'm preparing for swap.

[rallycinq]

The CIH blocks are pretty solid. I would take the head off and check before spending any money.

Cheers

D

[GemBoy]

spiney_norman, on 25 January 2012 - 10:19 PM, said:

You say your 1.9S was running on 3 cylinders, have you checked simple things like spark plugs, distributor cap, spark plug leads etc? Sounds like fixing your original engine would be cheaper and easier than sourcing the parts to swap to a C20NE unless there's something else wrong with it?

It turned out that there was a lot of dirt under distributor cap, silly me... It is working without any problems after cleaning (don't count overheating of course).
Ever more, engine still starting without problems, straight on LPG with almost-dead battery, and it's like -15^C (even colder at nights) since 2 weeks,
this engine still has some life inside...

[spiney_norman]

If it's overheating, check the thermostat and make sure there's no air in the coolant system!

[GemBoy]

spiney_norman, on 04 February 2012 - 04:33 PM, said:

If it's overheating, check the thermostat and make sure there's no air in the coolant system!

As i said before, probably engine block (or engine head, it wasn't checked under pressure) is broken, fumes are going to water cooling circuit and also i found some water traces in oil recently.

Thermostat was taken out as the first suspect of overheating.

[spiney_norman]

Definitely get the head pressure tested, it's most likely either that or the head gasket.

[monzta]

Its propably the head gasket. I would remove the head, and get the head tested. Normally the heads does not crack as they are gauss iron like the engine block and not a bolt together of two metals that act different to heat (like gauss block / aluminium head).

If all that needs doint is a skimming of the head, check that the head mounting surface is straight on the block, a new set of gaskets etc, i would not waste time and money to do a OHC build on a car thats born as a CIH.

As you are from Poland you also have got really good access to CIH engine parts from germany. If the old engine is shot it should not be hard for you to pick up a good 2,0E (or even a 2,2 / 2,4) CIH engine in Germany ? I think you will be more pleased with that solution.

The OHC and DOHC builds are immense in finding parts and bits that all fit together. The Astra engine is not a plug´n play deal, and neither is the Omega gearbox. Both has never been originally mounted in the car and that calls for alot of problemsolving when the build is going.. As for mounting a engine from another car brand like BMW, this just makes everything 10 times harder than with the C20NE.

So if your car is CIH , i would definatly keep it that way, and take advantage of your German neighbours